1. Field of the Invention
The present invention relates to fluid pumps and motors utilizing or producing rotary shaft power. More particularly, the present invention relates to fluid pumps and motors having primary and secondary vanes moving relative to one another to pump or be driven by fluid in the spaces between the vanes.
2. Background
The first recognized pump, which basically comprised a series of cups mounted on a conveyer for pumping water to a higher elevation, is thought to have been made by the ancient Egyptians in about 2000 BC. Operated in reverse, with the weight of water in the cups forcing the conveyor to rotate in the opposite direction, the ancient Egyptians possibly also used the same device as the first fluid motor. Since then, innumerable pumps have been developed for the purposes of raising, transferring, compressing and attenuating virtually every known type of fluid. Equally innumerable fluid motors have also been developed, which characteristically utilize the energy of a flowing stream to impart mechanical motion. Despite the long history of technological developments both of pumps and fluid motors, man continues in his manifest pursuit of the perfect fluidic machine for each application.
In the course of progress, numerous devices have been quite successful for converting shaft power to flow and vice versa. One of the most successful types of pumps in many applications is the rotary pump, which basically consists of at least two members which are rotated in a fashion such that the members positively displace fluid from an inlet to the proximity of an exhaust, at which point the fluid is exhausted by reduction of a space defined between the two members. Perhaps the most conventional of rotary pumps is the gear pump which consists of two counter-rotating gears which carry fluid in the spaces between their teeth and force evacuation of those spaces by a meshing of the two gears near the exhaust port. A variation of the gear pump utilizes an internal gear or belt meshed with an external gear in an analogous fashion.
Such devices, however, generally suffer from large size to displacement ratios, sliding surface contact, high complexity, and unjustifiable costs.
Many other problems, obstacles and deficiencies faced by the prior art and/or addressed by the present invention will be obvious to those skilled in that art, especially in light of the further descriptions herein.